Yes, Whiteny's cotton gin was a huge advancement. So was electricity, communication, the light bulb and a host of other things.

What really drove the massive "improvements" though, was the industrial revolution and the "invention" of the assembly line - the kudos probably go to Henry Ford for that. The idea that identical products could be mass produced so quickly and uniformly was unknown and was absolutely necessary for additional technology and production.

The cotton gin was an enormous help in growing cotton, but it stopped there. The assembly line was an enormous help in production of almost every product known. It even helped in such things as growing crops, where an assembly line concept is not possible, because it provided more "cotton gins" in the form of cheap and easily produced tools to aid in the production of those crops.

Actually the idea that identical products could be mass produced was much earlier than Henry Ford.Though he can lay claim to the assembly line mass production began with clocks when it was realised that it wasn't necessary to make each part individually and specific to one end product. That rather than having one man making all the parts for one clock, one man could make many identical and interchangeable parts and another could assemble them. Henry Fords innovation was that rather than one skilled man assembling a complete unit, many semi skilled men could perform just one or two functions in the assembly and that rather than them going to the work, the work came to them.

The invention of mass production should more rightly be laid at the door of Eli Terry who was mass producing clocks as early as 1806.

Interesting - I'd never heard of Terry. Wiki is a little vague, but it does indeed look like he was the first to introduce mass production of identical (or very, very similar) parts for later assembly.

And that was really the key; making lots of identical parts. Just as you say, that makes it possible for a worker to simply put them together, quickly and easily, rather than carefully either make each part as he needs it or modify it to fit.

I'd have to put that ability before bringing the work to the worker (assembly line).